Apparatus for heating air in dry spinning of artificial threads



APPARATUS PoR HEATING AIR IN DRY SPINNING 0F ARTIFICIAL THREADS Junge 7, 1932. A. FRIEDERICH ET AL Filed March 14, 1929 muawf o O O O Patented June 7, 1932 UNITED STATES PATENT yOFFICE ALFRED FRIEDERICH AND PAUL SCHII'ACK,` 0F BElRlIIN',r G-ERIVIAJ'TTY,` ASS](3`r1\l'0RSA r4T0 ACEIA G. M. B. H., OF BERLIN-LICHTENBERG,GERMANY, A CORPORATION 0F :GEB-

MANY

APPARATUS roR HEATING AIR IN DRY SPINNING or ARTIFICIAL THREADS y Application filed March 14, 1929, Serial No. 347,135, and in VGermany March 22, 1928.

Our present invention relates Vto a new apparatus useful in the manufacture of artificial silk according to the dry spinning process. One of its objects is to provide such an apparatus in which the air, necessary to evaporate the solvent of the spinning solution, is preheated in a very simple manner and uniformly in a plurality of spinning cells.

In the manufacture of artificial threads in the dry spinning process it is usual to preheat the dry air entering into the usually warmed spinning cells to definite temperature. This apparatus may be common to a whole row of spinning cells. A separate heating member can, however, also be provided for warming the air for each individual cell. In the first case it is difficult to maintain the air entering the individual cells at exactly the same temperature, more particularly if the air is relatively strongly preheated. In the second case the construction is complicated and expensive.

According to the present invention, the drawbacks of the two constructions are obviated in a simple and advantageous manner by heating the dry air by the heating apparatus of the spinning cells themselves. For this purpose cylindrical spinning cells are preferably used which are surrounded by a heating casing which is warmed by steam or by hot liquid or by an electric resistance coil.

According to the invention, an air casing, concentric to the external heating casing, is traversed by the incoming dry air for a portion or for the whole length of the heating surface. The air is heated in this path to a temperature slightly below that of the heating medium, but, by suiliciently increasing the heating surface, can approximate very closely to it. The air casing is, preferably, insulated against the loss of heat externally.

In the accompanying drawing we have illustrated a preferred form of the invention. Fig. l represents a vertical sectional view of an apparatus according to the invention and Fig. 2 is a top plan View of the same apparatus. The same reference characters are used in Figs. 1 and 2 to designate the same parts. In the drawing, A is a spinning cell of circular'cross section closed at both ends by plates B and C. In the upper plate B ani-nlet tube I) for the spinning solution is arranged bearing the spinning nozzle E. The threads F pressed through the spinning nozzle E into the spinning cell A leave the latter through a funnel-shaped-o-pening G provided in the lower plate C. The threads F are freed from the solvent during their passage through the spinning cell A by a current of warm air which passes through the cell :in the opposite direction. The warm airY enters the cell through holes H which are symmetrically arranged at the lower part vof the cell and the air laden with the vaporized solvents is dischargedfromkthe cell through the outlet J. K is a heating jacket which is narrowed at both ends K and is welded to the spinning cell A. A heating liquid L is circulated through this heating jacket, entering at the bottom thereof through the pipe M and leaving at the top through the pipe N. The

heating jacket K is surrounded concentrically by a second jacket O, which is spaced somewhat froin thejacket K, and which is open at theV top but is provided with a funnel shaped lower end O extending just below` the holes H in the spinning cell where it is firmly attached to the spinning cell. The air space thus formed is in communication with the holes H. 'The drying air enters the top of the circular air space between the heating jacket K and the outer acket O at the point P and is sucked in the direction of the arrows through the holes H into the spinning cell A, leaving the latter through the outlet J. During its passage through the said air space the drying air is in contact with the outer surface of the heating jacket K and is gradually warmed in this manner so that when entering the spinning cell A its ternperature is only a few degrees below the teinperature of the heating liquid L. In order to avoid loss of heat, the outer jacket O is surrounded by an insulating layer Q.

Having thus described the nature of our said invention and the best means we know of carrying the same into practical effect, we claim v 1. In an apparatus for spinning artificial1 silk according to the dry spinning process i in combination, a tubular spinning cell provided at its top with means to supply the spinning solution in form of threads and at its bottom with an opening for discharging the threads formed, means for admitting uniformly the drying airl at the lower part and an outlet for the air at the upper part'of the spinning cell, heating means surrounding the cell and a casing external to thesaid heating v means, open at the top and in connection with the inlet openings of the spinning cell traversed by the drying air.

2. In an apparatus for spinning artificial silk according to the dry spinning process in combination, a tubular spinningcell pro- Y vided at its top with means to supply the Y spinning solution in form of threads and at its bottom with an opening for discharging the threads formed, said cell being provided further with symmetrically arrangedholes at its lower part and an outlet tube at its upper part, a heating jacket surrounding said spinning cell, and a casing external to the said heating jacket in communication with the holes at the lower part of the cell and insulated against loss of heat externally said casing being open at the top.

In testimony whereof, we affix our signatures.

ALFRED FRIEDERICH. PAUL SCHLACK. 

